1. Field of the Invention
The present invention relates to an engine speed control system for a snow remover.
2. Description of the Related Art
Widely known in conventional practice are snow removers in which an internal combustion engine is mounted, a snow removal mechanism (such as auger or blower) is driven with the engine, and a travel mechanism (such as crawler) is also driven by the engine to allow the snow remover to be self-propelled, for example, as taught in Japanese Laid-Open Patent Application No. 2001-20238.
In snow removers wherein a snow removal mechanism or a travel mechanism is driven by the engine, a throttle valve is conventionally opened and closed by a mechanical governor in response to the engine load, whereby the engine speed is controlled so as to reach the desired speed.
The mechanical governor operates so as to maintain a constant engine speed (specifically, the desired speed) by means of the balance between a load generated by a flyweight and the elastic force of a spring. Therefore, it has been impossible to set the desired speed during a high engine load (high load acting on the snow removal mechanism or travel mechanism) to a level above the speed during a low engine load (low load acting on the snow removal mechanism or travel mechanism). Therefore, conventional snow removers have been disadvantageous in that the engine speed increases as the load acting on the snow removal mechanism or travel mechanism decreases, more noise is generated, and more fuel is consumed.
Also, in snow removers based on the prior art, when the engine speed (engine output power) is either too high or too low relative to the load (in other words, the snow quality or the amount of accumulated snow) acting on the snow-removal mechanism or travel mechanism, the user is compelled, based on experience, to manually vary the mechanical governor setting and adjust the engine speed. Accordingly, the operation becomes more complex, and load generating operations such as snow removal and driving become more difficult to perform in a stable manner.